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Exploring Unga's bulk copper-gold targets


Last updated 12/6/2019 at 7:03am

Alaska State Library – Historical Collections

Established in 1886, the historic Apollo gold mine on Unga Island was the first hardrock gold operation established in the Alaska territory. Apollo and adjacent Sitka mine produced roughly 150,000 ounces of gold from high-grade epithermal veins before they were shuttered in 1922.

Redstar Gold Corp. Dec. 2 said it has identified a 10-kilometer-long trend on its Unga project in Alaska that hosts seven, kilometer-scale alteration zones and several smaller ones capable of hosting bulk tonnage copper and gold mineralization in porphyry and epithermal systems.

The Unga project, which is on the Unga and Popov islands just south of the Alaska Peninsula, is best known for its high-grade gold. According to historical reports, the Apollo and adjacent Sitka mines produced roughly 150,000 ounces of gold from high-grade epithermal veins before they were shuttered in 1922.

Much of Redstar's exploration in recent years has focused on two high-grade gold trends – Apollo-Sitka and Shumagin – that each cut roughly six miles across Unga Island. Apollo-Sitka hosts the historic Apollo Mine and Shumagin is a parallel high-grade gold trend about 2,000 meters to the northwest.

The company, however, has also been looking at previously identified lower grade bulk tonnage potential north of these trends that were never followed up on due to low gold prices of the time.

"Redstar's high-grade gold targets on the Shumagin and Apollo-Sitka trends in the south of Unga Island remain key to the company's development, but this broader targeting exercise is designed to show the bulk tonnage copper and gold potential in the north of Unga Island where previous exploration efforts in the 1980s (historic price at the time of US$400-450 price gold) led to discovery of intrusive and vein-hosted gold, copper and silver," said Redstar Gold President John Gray.

Redstar said interpretation of satellite data has revealed zones of clay alteration, silicification and iron distribution typical of mineralized porphyry and epithermal systems in the Pacific Rim Ring of Fire tectonic belts. This up-to-date study clearly demonstrates that positive exploration results from a 1980s campaign are contained within a 10-by-four-kilometer trend, according to the company.

This work was designed to gain a better understanding of the Zachary Bay, Thormac, Irish and Hog prospects, where gold and significant copper has previously been identified in surface sampling and drilling.

One hole drilled into Zachary Bay porphyry target area in 1975 cut 107 meters averaging 0.28 grams per metric ton gold and 0.11 percent copper.

One surface sample from Hog, an epithermal target about 5,000 meters northwest of Zachary Bay, contained 4.75 g/t gold and 268 g/t silver. One hole drilled at this target in 1983 cut 1.8 meters averaging 2.38 g/t gold and 16.5 g/t silver, and 0.61 meters 2.81 g/t gold and 24.7 g/t silver.

One surface sample collected from Irish, which is about 3,500 meters northeast of Zachary Bay, contained 2.5 g/t gold; and a sample at Thormac, about 1,500 meters southeast of Irish, contained 1.19 g/t gold.

Zachary Bay gold silver copper exploration map Unga Island Alaska

Redstar Gold Corp.

"Overlaying the satellite imagery in this area establishes a strong correlation between surface silica, clay alteration and iron oxide and historic drilling success in finding copper-gold porphyry mineralization," said Gray.

Seven additional mineralized systems in this area – Amy, Benjamin, Bruce, James, Peter, Sandra and Sherry –have not yet been systematically explored.

"The seven new target areas are in addition to the underexplored areas of the Zachary Bay-Antoinette aureole, which has a diameter of three kilometers, and the adjacent 1.8-kilometer-wide Zinc Breccia zone," Gray added. "These alteration-mineralization systems are an exciting add-on to our known high-grade gold epithermal systems and are big enough targets to host large-scale economic deposits that are of a size that will interest major mining companies and merit further exploration investment."


Unga high grade gold silver copper exploration property map AlaskaZachary Bay gold silver copper exploration map Unga Island Alaska


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